/*
 * Copyright (c) 2023 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/**---
 description: >
    TypeScript has a way to describe objects which have unknown keys but known values on an object, via index signatures.
 module: ESNext
 isCurrent: true
 ---*/


import { Assert } from '../../../suite/assert.js'

interface I1 {
    name: string;
    age: number;
    [pName: string]: string | number;
}
let env: I1 = {
    name: "lll",
    age: 22,
};
function fun(op?: I1): I1 | undefined {
    if (op) {
        Assert.isString(op.name);
        Assert.isNumber(op.age);
    };
    return op;
};
let env2 = fun(env);
Assert.equal(env2!.name, "lll");
Assert.equal(env2!.age, 22);